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Heater - Not blowing cold air

Discussion in 'Generation 1 Prius Discussion' started by topgear3793, May 8, 2018.

  1. topgear3793

    topgear3793 New Member

    Joined:
    May 8, 2018
    6
    0
    0
    Location:
    San Jose CA
    Vehicle:
    2003 Prius
    Model:
    N/A
    Hi all,

    Just purchased my first Prius today, first gen 2003. Love it.

    Only thing I have noticed so far is that the heater is not blowing hot air (AC works great though).

    Engine coolant overflow reservoir is low, so I will be picking up some coolant at Toyota tomorrow. That being said, I did read the heater error codes as suggested by some other threads on this issue, and I saw codes 31 and 41.

    I could not find a reliable source to see what these codes mean? I even paid $15 for a Toyota TechInfo subscription, and cannot seem to find a service manual, only the owner's manual.

    Any info on these codes, or how to find the service manual through TechInfo, would be greatly appreciated!
     
  2. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,072
    14,976
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    It sounds as if maybe you didn't completely sign in after setting up your subscription. The owner's manual you found is out on the part of the site you can access without signing in.

    Once you are signed in, look for (and click) the TIS tab (for technical information service). Things should look more or less as described in this post.

    Your 31 and 41 codes have to do with the position sensor circuit for the air mix damper. That's the one that controls the temperature of supplied air by varying how much goes through the heater core and how much goes around it. Naturally, if the car has trouble positioning that damper (or sensing where it is positioned), you won't get out the air temperature you expect.

    I had to clean the position sensor on my Gen 1 air mix damper once ... I made this post about it.

    -Chap
     
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  3. topgear3793

    topgear3793 New Member

    Joined:
    May 8, 2018
    6
    0
    0
    Location:
    San Jose CA
    Vehicle:
    2003 Prius
    Model:
    N/A
    Hey Chap,

    Thanks, I took a look at the little Denso unit under the dash and the arm had actually come off. Put it back in and heater works great, didn't even have to pull it out.

    Thanks!

    As for the TIS, called them and they casually said I had to reset my password 3 times before it would let me log in, and by the time they told me I had already wasted the $5. I'll avoid that in the future!
     
  4. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,072
    14,976
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    The system that they outsource to for handling logins and billing has got to be among the clunkiest around, and I sometimes let out a few choice words in the process of getting in. They could probably contract with PayPal or Square or the storefront option of their local cheapo webhosting outfit and have a smoother experience. Once you get in, though, it's a real wealth of information, well hyperlinked (very unlike the dead PDF copies you sometimes find on the web), and the interactive wiring diagram is a joy to use. Don't let the clunky front end forever stop you from knowing where the best information you can find about fixing your Prius is when you need it.

    Glad you got the mix linkage fixed. (y)

    -Chap